Year	%
1980	10.2
1986	9.9
1987	9.3
1991	9.1
1992	9.2
1993	9.3
1994	9
1995	8.4
1996	8.2
1997	8.2
1998	7.8
1999	8
2000	7.6
2001	7.1
2002	6.9
2003	7.6
2004	8.1
2005	8.3
2006	8.7
2007	8.6
2008	9.1
2009	9.4
2010	9.4
2011	9.6
2012	9.9
2013	10
2014	9.7
2016	9.7
2017	10
2018	9.9
2019	9.5
2020	9.4
2021	9.8
2022	10.1